a = int(input("请输入第一条边："))
b = int(input("请输入第二条边："))
c = int(input("请输入第三条边："))

if a <= 0 or b <= 0 or c <= 0:
    print("输入的边长有误")
elif a + b <= c or a + c <= b or b + c <= a:
    print("输入的边长有误(两边之和大于第三边)")
elif a == b or b == c or a == c:
    print("等腰三角形")
elif a == b and b == c:
    print("等边三角形")
elif a ** 2 + b ** 2 == c ** 2 or a ** 2 + c ** 2 == b ** 2 or b ** 2 + c ** 2 == a ** 2:
    print("直角三角形")
